公开(公告)号：US4914679A

公开(公告)日：1990-04-03

申请号：US223639

申请日：1988-07-25

申请人： Akio Tomiyama ,  Osamu Yokomizo ,  Yasuhiro Masuhara ,  Toshitsugu Nakao ,  Shin-ichi Kashiwai ,  Yoshishige Kawada ,  Hiromasa Hirakawa ,  Shigeto Murata

发明人： Akio Tomiyama ,  Osamu Yokomizo ,  Yasuhiro Masuhara ,  Toshitsugu Nakao ,  Shin-ichi Kashiwai ,  Yoshishige Kawada ,  Hiromasa Hirakawa ,  Shigeto Murata

IPC分类号： G21C3/10 ,  G21C3/33

CPC分类号： G21C3/3315 ,  Y02E30/40

摘要： A fuel assembly according to the present invention is formed in such a manner that the small diameter portion of an upper end plug of a fuel rod is inserted into a boss of an upper tie-plate. The upper end plug includes a small diameter portion and a large diameter portion which is disposed below the former. An expansion spring in disposed in the small diameter portion of the upper end plug. A cover member surrounding this expansion spring is disposed in the large diameter portion of the upper end plug, and extends upwardly. Since the cover member surrounds the expansion spring, pressure loss caused by the expansion spring can be reduced.

摘要翻译： 根据本发明的燃料组件形成为使得燃料棒的上端塞的小直径部分插入上连接板的凸台中。 上端塞包括一个小直径部分和一个大直径部分，该部分设置在前者的下方。 膨胀弹簧设置在上端塞的小直径部分中。 围绕该膨胀弹簧的盖构件设置在上端塞的大直径部分中并向上延伸。 由于盖构件围绕膨胀弹簧，所以可以减小由膨胀弹簧引起的压力损失。

公开(公告)号：US5106575A

公开(公告)日：1992-04-21

申请号：US464151

申请日：1990-01-12

申请人： Shozo Nakamura ,  Tadashi Mizuno ,  Tetsuo Yasuda ,  Akira Maru ,  Yoshishige Kawada ,  Yoshihiko Yanagi ,  Hiromasa Hirakawa ,  Junjiro Nakajima ,  Yasuhiro Aizawa ,  Yorihide Segawa

发明人： Shozo Nakamura ,  Tadashi Mizuno ,  Tetsuo Yasuda ,  Akira Maru ,  Yoshishige Kawada ,  Yoshihiko Yanagi ,  Hiromasa Hirakawa ,  Junjiro Nakajima ,  Yasuhiro Aizawa ,  Yorihide Segawa

IPC分类号： G21C3/322

CPC分类号： G21C3/322 ,  G21Y2002/201 ,  G21Y2002/303 ,  G21Y2004/30 ,  G21Y2004/302 ,  Y02E30/38

摘要： A nuclear fuel assembly has a plurality of fuel rods and a lower tie plate supporting their lower ends. Coolant apertures extending through the lower tie plate. A channel box surrounds the fuel rods and receives the lower tie plate, to confine the coolant. To restrict leakage of coolant between the tie plate and the channel box, the coolant apertures include, adjacent the periphery of the lower tie plate, a plurality of peripheral apertures which are located at least partly outside the outermost fuel rods. The peripheral apertures each provide a coolant velocity peak located further from the axial center line of the tie plate than the axial center lines of the closest neighboring fuel rods. The invention also provides venturis in the leakage path between the channel box and the tie plate, to restrict deformation of the tie plate.